Q.Lyon Series Hypericum-Perennial?
This shrub has frozen back to the ground the last 2 winters. Evidently it is not winter hardy at location 40165. Should I cut it back each year?
This plant dies back to the ground in the colder parts of it's range, garden zones 5-9. Since it blooms on new wood, this is OK. This is just like butterfly bush, Buddleia , and bluebeard, Caryopteris. Both die back to the ground in colder climates but comes roaring back in spring. People living in warmer winter areas often cut their Hypericum back to 8 inches or so in early spring. I would leave the shrub intact for the winter as it will trap leaves and give it some additional winter protection. The following article explains what agricultural "zones" are. You can use it to find your zone. https://www.gardeningknowhow.com/...zones/usda-planting-zone-map.htm
